TK ( = Y. 



{.he pr : . the proximal ends of some of [be ; 



n the wall of the heart (p. 231). The proximal ends of t 

 become wider, the ; ->ut, and the walls of the tubules become in- 



cluded in the wall of the pelvis. In certain parts of the pelvic wall this process 

 goes on until deep baysthe calyces are formed, into which a large number of 

 tubules open. In the other parts of the wall the process does not go so far, thus 

 leaving promontories the renal papilla upon which larger tubulos or papil- 

 lary ducts open. The adult renal pelvis thus consists of the primi'i \v pelvis plus 

 the proximal ends of the straight tubules. 



Metanephric 

 blastema 



. 551. From a transverse section of a huma; V'.vrlng of the 5th week. 



The plane of the section is indicated in Fig. 549. Schr 



The Convoluted Renal Tubules and Glomeruli. 

 tlu- metanephric blastema or nephrogenic tissue surrounds the r. 



i tubules. It represents a condensation of tru and is 



rl'to give rise to the convoluted tubules and glomeruli. The cells of the 

 ma in the region of the ampulke of the term; : les acquire 



.'.hrlial character and become arranged in solid in :3). Each 



.n ampulla and acquires a lumen, which becomes 



witti the 1 of the straight tubul men . longates and forms an SV 



structure 54 and 355). <- The loop of the S nearer the straight ti 



elongates stul more ar> toward the pelvis, parallel with ti 



